Grok itself seems to give another explanation: https://x.com/_shift_MIND/status/1944332505068327253

I can’t scroll. It just says 910 replies underneath and if I click on that, it asks me to make an account. Perhaps X should allow me to see a thread if it wants me to apply context to what I am seeing. Having their chatbot spout hitler shit doesn’t really increase my desire to create an account.

You can read the thread here: https://xcancel.com/goodside/status/1944266466875826617

Or, alternatively, why would I build a product on this service? (In this vein, xAI is introducing an aligned version for commercial use, I think.)

Well the DoD just signed a contract with xAI, presumably because they asked "are we the baddies?" And then said "right, yes, very good then"